1. Field of the Invention
The present invention relates generally to a device for the relief of nausea, disorientation, and other disabling symptoms resulting from sensory mismatch and, more particularly, to an artificial labyrinth which provides the user an alternate means of determining his actual, physical orientation with respect to the surrounding environment.
2. Background of the Invention
Motion sickness does not discriminate. It can attack anyone, at any time. It is always disabling, to a greater or lesser degree, depending on the person. It is known from research that certain types of sensory mismatch are the leading cause of motion sickness. This mismatch occurs when the brain perceives that the body is in motion (through signals originating in the labyrinth and transmitted to the brain by the vestibular nerve system), but the motion sensed does not match what the eye can see and verify. The reverse is also true (i.e. sensory mismatch may also occur when the eye perceives motion, but the labyrinth does not provide confirming signals to the brain). There are many causes of this mismatch, including: time delay between the arrival of labyrinth motion signals and visual confirmation signals within the brain, or conflict between these signals when they do manage to arrive at the same time. In addition, the labyrinth's signals may be corrupted by various physical defects, conflict with each other within the labyrinth, or be missing entirely, as is the case when a person has the vestibular system disconnected (via operation, accident, or birth defect). All causes of this type of sensory mismatch are not precisely known, but it is well-established that such conditions can drastically affect an individual's quality of life and performance of everyday tasks.
One example of sensory mismatch is vertigo, which is the sensation the brain encounters when it perceives that the body is in motion (when in fact there is no motion), and it attempts to correct bodily posture to counteract the perceived physical sensation. Another example of sensory mismatch occurs when the eye perceives motion, but no motion actually occurs. This can be described as a type of "virtual reality" sickness, which is normally experienced users of video games or flight simulators. The reverse situation, when the body feels motion but there are no visual cues, is a much more common occurrence. Examples include: passengers in an airplane with no access to a window, sailors in a submarine, and ship passengers that cannot see the horizon. Such persons sense actual changes in body position, but have nothing in the environment which allows their eye to confirm the motion they perceive.
It is not clear why some persons can tolerate sensory mismatch better than others. However, at some point, almost everyone is affected when the mismatch is severe. This is especially true for those who, through accident or genetic deficiency, suffer from vestibular system disfunction. That is, even though the person is sitting or standing in a stationary fashion, they have the constant feeling of motion and, as a result, sickness. Simply bending over or slight movement of any kind may result in total disability in these cases. In the United States alone, over 30,000 vestibular section operations occur each year to help those suffering from Meniere's disease (i.e. vertigo induced by a distended labyrinth) get some relief, which drugs alone can't provide. However, rehabilitation after such an operation may require months of therapy.
Several attempts have been made to alleviate the symptoms of motion sickness (e.g., drugs which numb the nervous system and give some relief from nausea), but no successful product exists to eliminate the cause of motion sickness. Even if the resulting nausea is somewhat lessened, the sensory mismatch still exists, and may cause the affected person to make improper or dangerous decisions when accomplishing everyday tasks, such as driving an automobile.
Thus, there exists a long-felt and widespread need to provide alternative environmental orientation information (i.e. "visual cues") which can be used by the brain to replace erroneous or missing sensation signals normally provided by the natural labyrinth, and which can be readily confirmed by the natural vision system. The method and apparatus of the present invention, discussed in greater detail below, clearly satisfies this need.